--- src/constraint.c.orig	2015-05-09 18:58:56.300462567 +0200
+++ src/constraint.c	2015-05-09 18:59:02.979453950 +0200
@@ -257,7 +257,7 @@ constraint_check_child(void)
 	pid_t			 pid;
 
 	do {
-		pid = waitpid(WAIT_ANY, &status, WNOHANG);
+		pid = waitpid(-1, &status, WNOHANG);
 		if (pid <= 0)
 			continue;